Virginia Gov. Bob McDonnell (R) said Tuesday that he has ordered a full review of the state's textbook adoption process in the wake of a Washington Post report that a three-teacher state panel approved a fourth-grade history book that claims thousands of African Americans fought for the Confederacy during the Civil War.

Professional historians have disputed the claim, which the author of "Our Virginia: Past and Present" said she found using Internet resources written largely by the Sons of Confederate Veterans. The group has long maintained that large numbers of black soldiers fought for the South during the war, and played down slavery's role as a cause of the conflict .

In his first public comments on the textbook controversy, McDonnell said on WTOP's "Ask the Governor" radio program that he was "very disappointed" to learn of the situation. He said that the book should not have been approved for use in Virginia classrooms given the passage, which he called "outside the historical mainstream."

McDonnell's comments are particularly notable because the governor was the subject of national scrutiny after issuing a proclamation in honor of Confederate History Month in April that failed to mention slavery. McDonnell quickly apologized and amended the proclamation to refer to the abomination of slavery. This fall, he delivered an impassioned speech calling for racial reconciliation and promised that next April he would issue a broader Civil War commemoration proclamation instead of a document that honors the Confederacy.

Five Ponds Press, the publisher of "Our Virginia," has said that it will provide a sticker to cover the disputed passage and that the information will be removed in the second edition.

The Virginia Department of Education said last week that it would begin a comprehensive review of the textbook adoption process, focusing on committees that are charged with reviewing materials that deal with "sensitive periods in American history," said Charles Pyle, a department spokesman.

Virginia is one of 20 states that have a textbook adoption processes, intended mostly to ensure that textbooks adhere to state Standards of Learning, and Virginia officials have long said that the state's textbook review process is among the country's most comprehensive.

But five of the 10 committees assigned to review elementary school social studies textbooks in Virginia last year did not include a single content specialist.

McDonnell said he was concerned that "Our Virginia" was reviewed by just three elementary school teachers, indicating more input may be needed in the process.

"I've directed my secretary of education to find out how that happened," McDonnell said. "I'm looking at not only what happened here, but also the entire process. I'm very disappointed that this error occurred. We fixed that one right away, and now we're looking at whether the process should be improved."

Loudoun County school officials have decided to pull "Our Virginia" from the district's fourth-grade classrooms , while officials in Fairfax and Arlington counties said they will continue to use the book. Prince William County is in the process of adopting textbooks, and "Our Virginia" is among those being considered.